1. Field of the Invention
The present invention relates to attaching an airbag to the interior of a vehicle. More specifically, the present invention relates to a blow molded knee airbag with an integrated reaction plate for mounting to a vehicle.
2. Description of Related Art
Inflatable airbags enjoy widespread acceptance as passive passenger restraints for use in motor vehicles. This acceptance has come as airbags have built a reputation of preventing numerous deaths and injuries as the result of years of development, testing, and use. Studies show that in some instances, the use of frontally placed vehicular airbags can reduce the number of fatalities in head-on collisions by 25% among drivers using seat belts and by more than 30% among unbelted drivers. Other statistics suggest that in a frontal collision, the combination of a seat belt and an airbag can reduce the incidence of serious chest injuries by 65% and the incidence of serious head injuries by up to 75%. These numbers and the thousands of prevented injuries they represent demonstrate the life-saving potential of airbags and the need to encourage their use, production, and development.
As a result in part because of the benefits such as those described above, automakers are now required to install airbags in most new vehicles manufactured for sale in the United States. Many automobile manufacturers have turned this airbag technology requirement into a marketing tool. Enticed by the promise of added safety, vehicle purchasers frequently seek out vehicles with sophisticated airbag systems.
Airbags may be mounted in vehicular panels near the steering wheel, in the region or components of the glove box, in vehicle doors, along vehicle roof rails, walls, vehicle floors, or beneath a dashboard to provide deceleration in specific types of collision events.
As experience with the manufacture and use of airbags has progressed, the engineering challenges involved in their design, construction, and use have become better understood. Most airbag systems are designed to rapidly inflate and provide a cushion in front of or alongside an occupant based on a presumption that the occupant will be in a predetermined position. Problems have been observed when the occupant is “out of position” when a collision occurs and the airbag deploys. Similar problems may occur when the occupant is deflected away from the airbag before proper deceleration can occur.
Out-of-position injuries may be attributed in part to the fact that most airbag systems deploy in front of the torso of an occupant. More specifically, these conventional airbags deploy between the upper torso of an occupant and the windshield and instrument panel. During a front-end collision, there is a tendency for an occupant, particularly one who is not properly restrained by a seat belt, to slide forward along the seat. This results in poor kinematics and positioning when the occupant interacts with a frontal airbag, such as a driver or a passenger's side airbag.
During a front end collision, there is a tendency for an occupant, particularly one who is not properly restrained by a seat belt, to slide forward along the seat and “submarine” under the airbag (hereinafter referred to as the “primary airbag”). When the occupant submarines, the primary airbag is less effective in protecting the occupant. Such submarining causes the vehicle occupant's knees to contact the instrument panel or structure beneath the panel. Further injuries can occur when the occupant's legs move forward such that the knees are trapped in or beneath the instrument panel just before the foot well collapses. As the foot well collapses, the vehicle occupant's feet are pushed backward, which causes the knees to elevate and become further trapped. As the foot well continues to crush, the load on the trapped legs increase and can cause foot, ankle, and leg injuries.
In order to improve occupant protection, knee airbag systems have been developed. Knee airbag systems typically engage an occupant's knees or lower legs and prevent submarining under the primary airbag. Knee airbag systems are generally positioned in the lower portion of the instrument panel. Typical knee airbag systems include a knee airbag and an inflator. The inflator, once triggered, uses compressed gas, solid fuel, or their combination to produce rapidly expanding gas to inflate the airbag. The inflated knee airbag occupies a generally rectangular volume of the vehicle leg compartment. These systems hold the occupant in place on the seat, and improve the kinematics for the occupant.
Such knee airbag systems often include a knee airbag, a reaction plate, and a panel. The panel, referred to as a knee bolster panel is disposed forward of the knee airbag. The reaction plate is typically required by a knee airbag system to allow the air bag to expand or deploy in the correct direction. In some cases the reaction plate is a part of the instrument panel. In other cases, often due to vehicle assembly concerns, the reaction plate may be part of the knee airbag module. Having the reaction plate on the module may complicate how the reaction plate is attached to the airbag. Typically mechanical fasteners, such as rivets, or screws are used to attach the reaction plate to the airbag.
However, the use of mechanical fasteners may create additional labor, part, and design expenses. For example, holes must be machined into the airbag such that the fasteners can effectively attach the two parts. Moreover, it is labor intensive and time consuming to use mechanical fasteners. The design expenses also increase because the installation order and process of the knee airbag system must be considered in designing these types of covers. When these additional expenses are incurred with respect to a large number of vehicles, the total expense can be substantial.
Accordingly, there is a need in the art for a novel knee airbag system that addresses one or more of the above-listed problems. Such a system is disclosed herein.